Various patents disclose apparatus and systems for storing energy and converting power from one form into another. For example, the U.S. Pat. No. 3,970,917 to Diggs discloses a system for storing energy and converting DC power to AC power. The system includes a flywheel which is mounted in an evacuated housing and is driven by a plurality of wheels powered by DC electric motors which receive current from a DC input power source. A number of wheels are coupled to AC generators which selectively engage the rotating flywheel to withdraw energy from the rotating mass of the flywheel in the form of alternating current.
Various prior art patents utilize a flywheel to provide extra power on a standby basis. Examples of such systems include U.S. Pat. Nos. 3,558,901, to Jacobus, 3,477,013, Smith 4,027,485 Wallis, and 3,296,451 Van Ausdal.
Other engines generally of the type to which this invention relates are disclosed by the U.S. Pat. Nos. of 3,364,787, Miller, 2,301,424, List, 2,672,566 Heins and 4,218,624 Schiovanne.